Method for characterizing graphene on platinum substrate

Abstract

A method for characterizing graphene on a platinum substrate, including: coating a methylene blue developing solution to a platinum substrate having a surface covered with graphene, so that the methylene blue developing solution reacts with hydrogen-containing gas under catalysis of platinum to yield colorless methylene white; after the pressure is restored, methylene white in the exposed area of platinum substrate will quickly turn blue when it is oxidized into methylene blue by reacting with oxygen in the air under catalysis of platinum. Thus, color difference can be formed to facilitate the observation of the graphene. The characterization method is highly reproducible and simple, and can be used to characterize graphene with a large area on a platinum substrate. The characterization method does not damage the graphene and platinum substrate, has no negative impact on the quality of graphene, and the platinum substrate can be recycled to reduce costs.

What is claimed is: 
     
       1. A method for characterizing graphene on a platinum substrate, comprising the following steps:
 preparing methylene blue developing solution; 
 coating a platinum substrate with the methylene blue developing solution to obtain a sample, wherein the platinum substrate has a surface partially covered with graphene; 
 placing the sample in a reactor, and introducing a hydrogen-containing gas; 
 when a color change occurs in the sample, performing a vacuuming process to evaporate a solvent of the methylene blue developing solution; 
 unloading the vacuum, and observing the sample; and 
 after the observation, removing residue of the methylene blue developing solution, 
 wherein a device for observing the sample comprises an optical microscope or an electrical microscope; a method of removing the residue of the methylene blue developing solution comprises rinsing using one or a combination of aqueous solution, alcohol solution, and acetone solution. 
 
     
     
       2. The method for characterizing graphene on a platinum substrate according to  claim 1 , wherein a solvent of the methylene blue developing solution includes one or a combination of aqueous solution, alcohol solution, and acetone solution; a concentration of methylene blue in the methylene blue developing solution is in a range of 0.2 g/L-2.0 g/L. 
     
     
       3. The method for characterizing graphene on a platinum substrate according to  claim 1 , wherein the platinum substrate includes one of a platinum film, a platinum alloy film, a platinum foil, and a platinum bulk; wherein the platinum alloy includes one or a combination of copper platinum, iron platinum, cobalt platinum, nickel platinum, chromium platinum, tungsten platinum, molybdenum platinum, and manganese platinum. 
     
     
       4. The method for characterizing graphene on a platinum substrate according to  claim 1 , wherein a method of covering the platinum substrate with the graphene comprises preparing the graphene on the surface of the platinum substrate using a chemical vapor deposition method, or transferring previously-prepared graphene to the surface of the platinum substrate. 
     
     
       5. The method for characterizing graphene on a platinum substrate according to  claim 1 , wherein the covering of the graphene on the surface of the platinum substrate comprises complete covering or partial covering, wherein the partial covering comprises partial covering according to a predetermined pattern. 
     
     
       6. The method for characterizing graphene on a platinum substrate according to  claim 1 , wherein a method of coating the platinum substrate with the methylene blue developing solution comprises one or a combination of spraying, spin-coating, and drop-casting. 
     
     
       7. The method for characterizing graphene on a platinum substrate according to  claim 1 , wherein the hydrogen-containing gas comprises one or a combination of pure hydrogen, hydrogen-nitrogen gas mixture, and hydrogen-argon gas mixture; wherein the hydrogen-containing gas has a hydrogen concentration in a range of 5%-100%, and a pressure in a range of 1 kPa to 1000 kPa. 
     
     
       8. The method for characterizing graphene on a platinum substrate according to  claim 1 , wherein a temperature within the reactor is in a range of 5° C. to 90° C. when the hydrogen-containing gas is introduced for reaction. 
     
     
       9. The method for characterizing graphene on a platinum substrate according to  claim 1 , wherein a pressure inside the reactor during the vacuuming process is in a range of 0.001 kPa-70 kPa.